Every year, prosthetic options for amputees get better. One recent improvement is a flexible foot, currently in development at the University of Michigan. It recycles the energy of motion, making it less tiring for users to walk longer distances:

For amputees, what they experience when they're trying to walk normally is what I would experience if I were carrying an extra 30 pounds," said Art Kuo, professor in the Univ. of Michigan departments of Biomedical Engineering and Mechanical Engineering.

Compared with conventional prosthetic feet, the new prototype device significantly cuts the energy spent per step.[...]

Based on metabolic rate measurements, the test subjects spent 14 percent more energy walking in energy-recycling artificial foot than they did walking naturally. That's a significant decrease from the 23 percent more energy they used in the conventional prosthetic foot, Kuo says.

"We know there's an energy penalty in using an artificial foot," Kuo said. "We're almost cutting that penalty in half."

Link via Make (which has information about other advanced prosthetic feet) | Image: Steve Collins, University of Michigan

The most amazing spirit lift I have ever seen was while I was talking to a 60-year-old with a recent amputation when a couple of bus loads of teenage amputees showed up. The sight of young women in short skirts flirting with young men while showing off shapely legs and high tech appliances had her rethinking.